/**
 * @author SaoE
 * @date 2025/3/25 16:29
 */
public class _21 {
    public ListNode mergeTwoLists(ListNode list1, ListNode list2) {

        if (list1 == null) {
            return list2;
        }
        if (list2 == null) {
            return list1;
        }
        if (list1.val < list2.val) {
            list1.next = mergeTwoLists(list1.next, list2);
            return list1;
        } else {
            list2.next = mergeTwoLists(list1, list2.next);
            return list2;
        }
    }



}
